What is a tosylate group?

1 Answer
Jul 19, 2016

A tosylate is the anion of tosylic acid.

This is tosylic acid (or p-toluenesulfonic acid):


so the conjugate base is a tosylate. It is toluene (methylbenzene) with a sulfonate group attached on the 4-position.

Related are tosyl leaving groups because they are large and they tend to have a low #"pKa"# (making them thermodynamically unstable, i.e. making their bonds weak).

A common "tosyl" compound is tosyl chloride.


NOTE: These actually have sulfonyl groups, not to be confused with sulfonate groups.